docs: def paint_with_alpha(self, alpha):
          """A drawing operator that paints the current source everywhere
          within the current clip region
          using a mask of constant alpha value alpha.
          The effect is similar to :meth:`paint`,
          but the drawing is faded out using the :obj:`alpha` value.
  
          :type alpha: float
          :param alpha: Alpha value, between 0 (transparent) and 1 (opaque).
  
          """
          cairo.cairo_paint_with_alpha(self._pointer, alpha)
          self._check_status()